/Engine/Plugins/Runtime/NetworkPrediction/Source/NetworkPrediction/Public/NetworkPredictionComponent.h
Its also worth pointing out that nothing about being aUActorComponentis essential here. All that this component does could be done within anAActoritself. An actor component makes sense for flexible/reusable code provided by the plugin. But there is nothing stopping you from copying this directly into an actor if you had reason to.
[UCLASS](Programming/UnrealArchitecture/Reference/Classes#classdeclaration)(Abstract) class UNetworkPredictionComponent : public [UActorComponent](API\Runtime\Engine\Components\UActorComponent)
FNetworkPredict...
NetworkPredictionProxy
Proxy to interface with the NetworkPrediction system.
FReplicationPro...
ReplicationProxy_ServerRPC
ReplicationProxies are just pointers to the data/NetSerialize functions within the NetworkSim.